The present invention relates generally to the use of wireless communications and diagnostic systems in automotive vehicles.
The Environmental Protection Agency (EPA) requires vehicle manufacturers to install on-board diagnostics (OBD) for emission control on their light-duty automobiles and trucks beginning with model year 1996. OBD systems (e.g., computer, microcontrollers, and sensors) monitor the vehicle""s emission control systems to detect any malfunction or deterioration that causes emissions to exceed EPA-mandated thresholds. Such a system, for example, is an oxygen or nitrogen-sensitive sensor located in the vehicle""s exhaust manifold and tailpipe.
The EPA requires that all information monitored or calculated by OBD systems is made available through a standardized, serial 16-cavity connector referred to as the ALDL (Assembly Line Diagnostic Link) or OBD connector. All physical and electrical characteristics of this connector are standard for all vehicles sold in the United States after 1996. The EPA also mandates that, when emission thresholds are exceeded, diagnostic information characterized by OBD systems must be stored in the vehicle""s central computer so that it can be used during diagnosis and repair.
A second generation of OBD systems, called OBD-II systems, monitor emission performance and a wide range of additional data that indicate the performance of the host vehicle. For example, in addition to emissions, OBD-II systems monitor vehicle speed, mileage, engine temperature, and intake manifold pressure. OBD-II systems also query manufacturer-specific data, such as engine-performance tuning parameters, alarm status, and properties relating to entertainment systems. In total, OBD-II systems typically access hundreds of segments of data relating to the performance and make of the host vehicle.
In addition to the OBD-II systems, most vehicles manufactured after 1996 have electronic control units (ECUs) that control internal electromechanical actuators. Examples include ECUs that control fuel-injector pulses, spark-plug timing, and anti-lock braking systems. Most ECUs transmit status and diagnostic information over a shared, standardized electronic buss in the vehicle. The buss effectively functions as an on-board computer network with many processors, each of which transmits and receives data. The primary computers in this network are the vehicle""s electronic-control module (ECM) and power-control module (PCM). The ECM typically accesses sensors and microcontrollers that monitor or control engine functions (e.g., the cruise-control module, spark controller, exhaust/gas recirculator). The PCM typically controls or monitors ECUs associated with the vehicle""s power train (e.g., its engine, transmission, and braking systems).
When a vehicle is serviced (e.g., for an emissions or xe2x80x98smog checkxe2x80x99), data from the standardized buss can be queried using external engine-diagnostic equipment (commonly called xe2x80x98scan toolsxe2x80x99) that connect to the above-described 16-cavity electrical connector (called an xe2x80x98OBD-II connectorxe2x80x99 for vehicles made after 1996). The OBD-II connector is typically located under the vehicle""s dashboard. Data transferred through the connector to the scan tool includes data like that described above as well as xe2x80x98diagnostic trouble codesxe2x80x99 or xe2x80x98DTCsxe2x80x99 that identify a specific malfunctioning component of the vehicle. This makes the service process more efficient and cost-effective.
Some manufacturers include complex electronic systems in their vehicles to access and analyze the above-described data. These systems are not connected through the OBD-II connector, but instead are wired directly to the vehicle""s electronic system. This wiring process typically takes place when the vehicle is manufactured. In some cases these systems transmit data through a wireless network.
It is an object of the present invention to address the limitations of the conventional engine-diagnostic systems discussed above. Specifically, it is an object of the invention to both access and send data relating to emissions over a vehicle""s ODB-II connector using a remote, wireless system that connects to the Internet. The data are then analyzed and used to monitor the vehicle""s emissions output. This allows, for example, a remote, on-line emissionscheck for the vehicle that is done completely over the Internet.
In one aspect, the invention features a method and apparatus for remotely characterizing a vehicle""s exhaust emissions. The method features the steps of: 1) generating data representative of the vehicle""s emissions with at least one sensor disposed within the vehicle; 2) transferring the data through to a data collector/router that includes: i) a microprocessor; and ii) a wireless transmitter in electrical contact with the microprocessor; and 3) transmitting a data packet representing the data with the wireless transmitter over an airlink to a wireless communications system and then to a host computer.
xe2x80x9cData representative of the vehicle""s emissionsxe2x80x9d, as used herein, means data that can be analyzed or processed to infer, estimate, or predict the emissions of a particular vehicle. xe2x80x9cEmissionsxe2x80x9d means gaseous forms of the following compounds: hydrocarbons, oxides of nitrogen, carbon monoxide, or derivatives thereof.
In some embodiments the data can be transferred directly from the ECM/PCM to the data collector/router (i.e., the data collector/router is embedded in the vehicle). Alternatively the data is serially transferred through an OBD-II connector or an equivalent serial interface located within the vehicle to the data collector/router. In this case, xe2x80x9cequivalent serial interfacexe2x80x9d means any interface or connector that allows data to be queried from the vehicle""s ECM. In this case, the data collector/router is typically located underneath the vehicle""s dash. In both cases, the generating step includes generating emissions data using one or more sensors (typically located in the vehicle""s exhaust manifold or tailpipe) that produce a signal in response to gas containing oxygen, oxides of nitrogen, or hydrocarbons.
The method also features the step of analyzing the data packet with the host computer to characterize the vehicle""s emissions performance. In this case, the analyzing step features the step of extracting data from the data packet corresponding to the vehicle""s emissions and storing the data in a computer memory or database. Once in the database, the data can be processed with an algorithm, such as a mathematical algorithm that predicts or estimates the emissions (e.g., an estimate of the concentration or amount of oxygen, oxides of nitrogen, or hydrocarbons) from the vehicle.
The analyzing step can also include the step of comparing the data with data collected at an earlier time to characterize the emissions performance of the vehicle. For example, the data can be compared to a predetermined numerical value or collection of values that represent xe2x80x98acceptablexe2x80x99 exhaust emissions. After the comparison, the method can further include sending an electronic text, data, or voice message to a computer, cellular telephone, or wireless device. The message describes a status of the vehicle""s emissions. In a related embodiment, the vehicle""s emissions status is displayed directly on a page on the Internet or World-wide web.
In still another embodiment, the method includes the step of sending a second data packet from the host computer system over an airlink to the wireless communications system and then to the data collector/router disposed in the vehicle. In this case, the second data packet is processed by the microprocessor in the data collector/router to generate a signal, and the signal is sent to at least one microcontroller disposed within the vehicle. The signal, for example, can be processed by the microcontroller and used to adjust one or more of its properties. For example, the signal can be used to xe2x80x98clear a DTCxe2x80x99 (i.e., change the DTC""s state from active to inactive) in the vehicle""s ECM.
In the above-described method, the terms xe2x80x98microcontrollerxe2x80x99 and xe2x80x98microprocessorxe2x80x99 refer to standard electronic devices (e.g., programmable, silicon-based devices) that can control and/or process data. xe2x80x9cAirlinkxe2x80x9d refers to a standard wireless connection (e.g., a connection used for wireless telephones or pagers) between a transmitter and a receiver.
Also in the above-described method, steps i)-iv) can be performed at any time and with any frequency, depending on the diagnoses being performed. For a xe2x80x98real-timexe2x80x99 diagnoses of a vehicle""s engine performance, for example, the steps may be performed at rapid time or mileage intervals (e.g., several times each minute, or every few miles). Alternatively, other diagnoses (e.g., a conventional emissionscheck) may require the steps to be performed only once each year or after a large number of miles are driven. Similarly, steps i)-iii) (i.e. the xe2x80x98generatingxe2x80x99, xe2x80x98transferringxe2x80x99, and xe2x80x98transmittingxe2x80x99 steps) may be performed in response to a signal sent from the host computer to the vehicle. Alternatively, the vehicle may be configured to automatically perform these steps at predetermined or random time intervals. In another embodiment, a vehicle""s emissions can be continually monitored, and the vehicle""s owner is only notified when the vehicle xe2x80x98failsxe2x80x99 the emissions test. In any embodiment described herein involving xe2x80x98passingxe2x80x99 or xe2x80x98failingxe2x80x99 an emissions test, the definition of xe2x80x98passxe2x80x99 or xe2x80x98failxe2x80x99 is determined by the appropriate regulating body, e.g. California Air Resources Board (xe2x80x98CARBxe2x80x99) or an equivalent state-wide organization, the Environmental Protection Agency (xe2x80x98EPAxe2x80x99), or a similar organization.
The invention has many advantages. In particular, wireless transmission of a vehicle""s emissions data makes it possible to remotely identify potential problems and perform xe2x80x98on-line emissions checksxe2x80x99 without bringing the vehicle to a conventional service center. In certain situations, this means potential problems with a vehicle""s emissions system can be rapidly determined, or in some cases remotely predicted and addressed before they actually occur. Moreover, emissions data from the vehicle can be queried and analyzed frequently and in real-time (i.e., while the vehicle is actually in use) to provide a relatively comprehensive diagnosis that is not possible in a conventional service center.
The device used to access and transmit the vehicle""s data is small, low-cost, and can be easily installed in nearly every vehicle with an OBD-II connector in a matter of minutes. It can also be easily transferred from one vehicle to another, or easily replaced if it malfunctions.
Communication with the vehicle""s OBD buss can also be bi-directional, making it possible to actually remotely address problems with the vehicle""s emissions system. For example, DTCs related to the vehicle""s emissions system can be cleared remotely.
Another advantage of the invention is that emissions data transmitted from a particular vehicle over a wireless airlink can be accessed and analyzed through the Internet without the need for expensive diagnostic equipment. Software used for the analysis can be easily modified and updated, and then used by anyone with access to the Internet. This obviates the need for vehicle service centers to upgrade diagnostic equipment for next-generation vehicles. The resulting data, of course, have many uses for vehicle owners, surveyors of vehicle emission performance (e.g., the EPA or J. D. Power), manufacturers of vehicles and related parts, and vehicle service centers.
Sophisticated analysis of the above-mentioned data yields information that benefits the consumer, vehicle and parts manufacturers, vehicle service centers, and the environment.
These and other advantages of the invention are described in the following detailed disclosure and in the claims.